The Ultimate Meaning of Life: Leaving a Legacy

This is part 2 of a two-part series.

In part one of this series, we asked what, if anything, makes life meaningful. We saw that some find meaning in behaving altruistically toward others, or toward the planet that sustains us, or in leaving a legacy by bringing children into the world.

Such behavior is adaptive, and the predisposition for it was likely selected, such that it is an innate part of our biological make-up. We also saw that we participate in not just biological evolution but also cultural evolution, and by generating creative works, we leave a cultural legacy.

To become a creative contributor to cultural evolution, one's mental representations—i.e., knowledge, memories, and beliefs—must merge into an integrated network during the first few years of life. I suggested that the drive to leave a cultural legacy isn't something we're born with, nor is it explicitly taught. Instead, it emerges from this conceptual network, which (from the inside) is experienced as a uniquely structured worldview.

Let's now explore how the capacity for such an integrated worldview emerges. The picture laid out here is an unproven theory, though one for which there is much converging evidence.

Approximately three million years ago, we evolved the ability to recursively refine an idea by considering it from different perspectives. This enabled us to escape the "here and now" by reconstructing the past or imagining the future. At this point, our mental representations were no longer separate; they joined together into little clusters of conceptual structure.

100,000 years ago
However, it wasn't until approximately 100,000 years ago that these disconnected islands grew significantly larger, and humans evolved the capacity to forge an integrated web of associations, a worldview (Gabora & Steel, 2017, 2020a,b). Although changes in the archaeological record were more gradual than once thought, this was nevertheless the birth of art, science, and religion.

Note that one can survive just fine without such an integrated worldview. One can do the right thing in response to the appropriate stimulus and even invent something new. But because one can't adapt ideas to new situations, they have little opportunity to build on one another, so there is little in the way of cumulative cultural change. Thus, until this point, culture is relatively static; it does not evolve.

Note that none of us comes into this world with such a worldview. We acquire this integrated structure during our first few years of life as we learn what exists and how these items of world knowledge are interrelated.

My colleagues and I have used autocatalytic networks to model how this integrated structure emerges in the first few years of life (Gabora, 1998; Gabora, Beckage, & Steel, 2022). There are biological factors that push humans toward the emergence of such a worldview.

Nurture also plays a role; caregivers coax their young to make connections and associations conducive to forming an integrated worldview. But neither nature nor nurture is sufficient; the crystallization of a worldview can be attributed to the mathematical properties of self-organizing networks.

Specifically, consider what happened as our brains grew, and we could increase the detail with which each memory is encoded. (For example, instead of encoding only that a particular plant has thorns, you also notice that it has pointy leaves and a hairy stem.) This gives you more ways of forging associations with other things in the memory, thereby engaging in a stream of thought. (Instead of just reminding you of other thorny things, it can also remind you of different plants with pointy leaves or hairy stems, or more generally, anything hairy.)

In graph theory, when the ratio of edges to nodes reaches ~0.5, the percolation threshold is crossed. At this point, short segments of connected nodes join to form a giant cluster encompassing most nodes. Here, nodes represent mental representations, and edges represent associations. As the number of mental representations increases, associations increase faster. Thus, they inevitably cross the percolation threshold, resulting in an integrated worldview.

Source: Adapted from (Gabora, 1998).

We can gain insight into what happens here by drawing on graph theory, which deals with network nodes (points) connected by edges (links). Here, the nodes represent mental representations, and the edges represent associations among them.

When the ratio of edges to nodes reaches approximately 0.5, the percolation threshold is crossed. At this point, short segments of connected nodes join to form a large cluster encompassing most nodes (see image).

The mind of a toddler
Now, consider what happens in the mind of a toddler. The toddler acquires mental representations (learns more about its world). Still, the capacity to forge connections between these mental representations increases more quickly than the number of mental representations (by an amount that depends on the average number of details with which each item is encoded).

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Therefore, it becomes inevitable that they (or at least some subset) collectively form an integrated network, a worldview (Gabora, 1998). I posit that this happens around age 3 or 4, and the drive to contribute to culture emerges from this newly forged worldview.

Now, we can see why nature and nurture are part of what drives us to leave a cultural legacy, but neither is sufficient. Evolutionary changes enable us to increase the detail with which each memory is encoded. Developmental changes due to individual and social learning increase the number of items encoded in memory.

But to get the mental representations to coalesce into an integrated structure, the percolation threshold must be crossed.

So, the idea, then, is that the urge to contribute to culture and leave a cultural legacy emerges from this second level of self-organizing structure, the network of mental representations that constitutes your unique worldview, which coalesces during the first few years of life and continues to grow and change throughout your life.

Read part 1 of the series here.